Jakarta, Indonesia ? Conservationists must protect tiger populations in a few concentrated breeding grounds in Asia instead of trying to safeguard vast, surrounding landscapes, if they want to save the big cats from extinction, scientists said.

Only about 3,500 tigers are left in the wild worldwide, less than one third of them breeding females, according to one of the authors of the study, John Robinson of the Wildlife Conservation Society.

Much has been done to try to save the world’s largest cat — threatened by over-hunting, habitat loss and the wildlife trade — but their numbers have continued to spiral downward for nearly two decades.

That’s in part because conservation efforts are increasingly diverse and often aimed at improving habitats outside protected areas, according to the study, published in Tuesday’s issue of the peer-reviewed PLoS Biology journal.

Instead, efforts should be concentrated on the areas where tigers live — most are clustered in just 6 percent of their available habitat — and especially where they breed.

“The immediate priority must be to ensure that the last remaining breeding populations are protected and continually monitored,” it says, adding if that doesn’t happen, “all other efforts are bound to fail.”

The WWF and other conservation groups say the world’s tiger population has fallen from around 5,000 in 1998 to as few as 3,200 today, despite tens of millions of dollars invested in conservation efforts.

The cats have been lost largely to poachers, who cash in on a huge market for tiger skins and a belief, prevalent in east Asia, that eating or applying tiger parts enhance health and virility.